Plant Physiology, Department of Horticulture, Agricultural Science Center North, University of Kentucky, Lexington, KY 40546, USA.
Biotechnol Biofuels. 2013 Oct 9;6(1):146. doi: 10.1186/1754-6834-6-146.
Improving saccharification efficiency in bioenergy crop species remains an important challenge. Here, we report the characterization of a Sorghum (Sorghum bicolor L.) mutant, named REDforGREEN (RG), as a bioenergy feedstock.
It was found that RG displayed increased accumulation of lignin in leaves and depletion in the stems, antithetic to the trend observed in wild type. Consistent with these measurements, the RG leaf tissue displayed reduced saccharification efficiency whereas the stem saccharification efficiency increased relative to wild type. Reduced lignin was linked to improved saccharification in RG stems, but a chemical shift to greater S:G ratios in RG stem lignin was also observed. Similarities in cellulose content and structure by XRD-analysis support the correlation between increased saccharification properties and reduced lignin instead of changes in the cellulose composition and/or structure.
Antithetic lignin accumulation was observed in the RG mutant leaf-and stem-tissue, which resulted in greater saccharification efficiency in the RG stem and differential thermochemical product yield in high lignin leaves. Thus, the red leaf coloration of the RG mutant represents a potential marker for improved conversion of stem cellulose to fermentable sugars in the C4 grass Sorghum.
提高生物能源作物的糖化效率仍然是一个重要的挑战。在这里，我们报告了高粱（高粱 bicolor L.）突变体 REDforGREEN（RG）的特征，作为生物能源饲料。
研究发现，RG 在叶片中积累了更多的木质素，而在茎中木质素减少，与野生型的趋势相反。与这些测量结果一致，RG 叶片组织的糖化效率降低，而相对于野生型，茎的糖化效率增加。木质素减少与 RG 茎的糖化效率提高有关，但 RG 茎木质素中 S:G 比值的化学位移也观察到增加。XRD 分析表明纤维素含量和结构相似，支持增加糖化性能与降低木质素之间的相关性，而不是纤维素组成和/或结构的变化。
在 RG 突变体的叶片和茎组织中观察到木质素的反式积累，这导致 RG 茎的糖化效率更高，而高木质素叶片的热化学产品产率不同。因此，RG 突变体的红叶颜色代表了 C4 草高粱中茎纤维素转化为可发酵糖的潜在改良标记。
